1 files changed, 121 insertions, 103 deletions

diff --git a/arch/powerpc/platforms/powernv/opal-irqchip.c b/arch/powerpc/platforms/powernv/opal-irqchip.c
index ecdcba9d1220..e180bd8e1400 100644
--- a/arch/powerpc/platforms/powernv/opal-irqchip.c
+++ b/arch/powerpc/platforms/powernv/opal-irqchip.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * This file implements an irqchip for OPAL events. Whenever there is
  * an interrupt that is handled by OPAL we get passed a list of events
@@ -5,11 +6,6 @@
  * interrupts to Linux so we implement an irqchip to handle them.
  *
  * Copyright Alistair Popple, IBM Corporation 2014.
- *
- * This program is free software; you can redistribute  it and/or modify it
- * under  the terms of  the GNU General  Public License as published by the
- * Free Software Foundation;  either version 2 of the  License, or (at your
- * option) any later version.
  */
 #include <linux/bitops.h>
 #include <linux/irq.h>
@@ -22,7 +18,7 @@
 #include <linux/kthread.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
-#include <linux/irq_work.h>
+#include <linux/of_irq.h>
 
 #include <asm/machdep.h>
 #include <asm/opal.h>
@@ -38,37 +34,44 @@ struct opal_event_irqchip {
 	unsigned long mask;
 };
 static struct opal_event_irqchip opal_event_irqchip;
-
-static unsigned int opal_irq_count;
-static unsigned int *opal_irqs;
-
-static void opal_handle_irq_work(struct irq_work *work);
 static u64 last_outstanding_events;
-static struct irq_work opal_event_irq_work = {
-	.func = opal_handle_irq_work,
-};
+static int opal_irq_count;
+static struct resource *opal_irqs;
 
-void opal_handle_events(uint64_t events)
+void opal_handle_events(void)
 {
-	int virq, hwirq = 0;
-	u64 mask = opal_event_irqchip.mask;
+	__be64 events = 0;
+	u64 e;
 
-	if (!in_irq() && (events & mask)) {
-		last_outstanding_events = events;
-		irq_work_queue(&opal_event_irq_work);
-		return;
-	}
+	e = READ_ONCE(last_outstanding_events) & opal_event_irqchip.mask;
+again:
+	while (e) {
+		int hwirq;
 
-	while (events & mask) {
-		hwirq = fls64(events) - 1;
-		if (BIT_ULL(hwirq) & mask) {
-			virq = irq_find_mapping(opal_event_irqchip.domain,
-						hwirq);
-			if (virq)
-				generic_handle_irq(virq);
-		}
-		events &= ~BIT_ULL(hwirq);
+		hwirq = fls64(e) - 1;
+		e &= ~BIT_ULL(hwirq);
+
+		local_irq_disable();
+		irq_enter();
+		generic_handle_domain_irq(opal_event_irqchip.domain, hwirq);
+		irq_exit();
+		local_irq_enable();
+
+		cond_resched();
 	}
+	WRITE_ONCE(last_outstanding_events, 0);
+	if (opal_poll_events(&events) != OPAL_SUCCESS)
+		return;
+	e = be64_to_cpu(events) & opal_event_irqchip.mask;
+	if (e)
+		goto again;
+}
+
+bool opal_have_pending_events(void)
+{
+	if (READ_ONCE(last_outstanding_events) & opal_event_irqchip.mask)
+		return true;
+	return false;
 }
 
 static void opal_event_mask(struct irq_data *d)
@@ -78,24 +81,9 @@ static void opal_event_mask(struct irq_data *d)
 
 static void opal_event_unmask(struct irq_data *d)
 {
-	__be64 events;
-
 	set_bit(d->hwirq, &opal_event_irqchip.mask);
-
-	opal_poll_events(&events);
-	last_outstanding_events = be64_to_cpu(events);
-
-	/*
-	 * We can't just handle the events now with opal_handle_events().
-	 * If we did we would deadlock when opal_event_unmask() is called from
-	 * handle_level_irq() with the irq descriptor lock held, because
-	 * calling opal_handle_events() would call generic_handle_irq() and
-	 * then handle_level_irq() which would try to take the descriptor lock
-	 * again. Instead queue the events for later.
-	 */
-	if (last_outstanding_events & opal_event_irqchip.mask)
-		/* Need to retrigger the interrupt */
-		irq_work_queue(&opal_event_irq_work);
+	if (opal_have_pending_events())
+		opal_wake_poller();
 }
 
 static int opal_event_set_type(struct irq_data *d, unsigned int flow_type)
@@ -136,16 +124,13 @@ static irqreturn_t opal_interrupt(int irq, void *data)
 	__be64 events;
 
 	opal_handle_interrupt(virq_to_hw(irq), &events);
-	opal_handle_events(be64_to_cpu(events));
+	WRITE_ONCE(last_outstanding_events, be64_to_cpu(events));
+	if (opal_have_pending_events())
+		opal_wake_poller();
 
 	return IRQ_HANDLED;
 }
 
-static void opal_handle_irq_work(struct irq_work *work)
-{
-	opal_handle_events(last_outstanding_events);
-}
-
 static int opal_event_match(struct irq_domain *h, struct device_node *node,
 			    enum irq_domain_bus_token bus_token)
 {
@@ -174,18 +159,23 @@ void opal_event_shutdown(void)
 
 	/* First free interrupts, which will also mask them */
 	for (i = 0; i < opal_irq_count; i++) {
-		if (opal_irqs[i])
-			free_irq(opal_irqs[i], NULL);
-		opal_irqs[i] = 0;
+		if (!opal_irqs || !opal_irqs[i].start)
+			continue;
+
+		if (in_interrupt() || irqs_disabled())
+			disable_irq_nosync(opal_irqs[i].start);
+		else
+			free_irq(opal_irqs[i].start, NULL);
+
+		opal_irqs[i].start = 0;
 	}
 }
 
 int __init opal_event_init(void)
 {
 	struct device_node *dn, *opal_node;
-	const char **names;
-	u32 *irqs;
-	int i, rc;
+	bool old_style = false;
+	int i, rc = 0;
 
 	opal_node = of_find_node_by_path("/ibm,opal");
 	if (!opal_node) {
@@ -201,7 +191,8 @@ int __init opal_event_init(void)
 	 * fall back to the legacy method (opal_event_request(...))
 	 * anyway. */
 	dn = of_find_compatible_node(NULL, NULL, "ibm,opal-event");
-	opal_event_irqchip.domain = irq_domain_add_linear(dn, MAX_NUM_EVENTS,
+	opal_event_irqchip.domain = irq_domain_create_linear(of_fwnode_handle(dn),
+				MAX_NUM_EVENTS,
 				&opal_event_domain_ops, &opal_event_irqchip);
 	of_node_put(dn);
 	if (!opal_event_irqchip.domain) {
@@ -210,67 +201,94 @@ int __init opal_event_init(void)
 		goto out;
 	}
 
-	/* Get opal-interrupts property and names if present */
-	rc = of_property_count_u32_elems(opal_node, "opal-interrupts");
-	if (rc < 0)
-		goto out;
+	/* Look for new-style (standard) "interrupts" property */
+	opal_irq_count = of_irq_count(opal_node);
 
-	opal_irq_count = rc;
-	pr_debug("Found %d interrupts reserved for OPAL\n", opal_irq_count);
+	/* Absent ? Look for the old one */
+	if (opal_irq_count < 1) {
+		/* Get opal-interrupts property and names if present */
+		rc = of_property_count_u32_elems(opal_node, "opal-interrupts");
+		if (rc > 0)
+			opal_irq_count = rc;
+		old_style = true;
+	}
 
-	irqs = kcalloc(opal_irq_count, sizeof(*irqs), GFP_KERNEL);
-	names = kcalloc(opal_irq_count, sizeof(*names), GFP_KERNEL);
-	opal_irqs = kcalloc(opal_irq_count, sizeof(*opal_irqs), GFP_KERNEL);
+	/* No interrupts ? Bail out */
+	if (!opal_irq_count)
+		goto out;
 
-	if (WARN_ON(!irqs || !names || !opal_irqs))
-		goto out_free;
+	pr_debug("OPAL: Found %d interrupts reserved for OPAL using %s scheme\n",
+		 opal_irq_count, old_style ? "old" : "new");
 
-	rc = of_property_read_u32_array(opal_node, "opal-interrupts",
-					irqs, opal_irq_count);
-	if (rc < 0) {
-		pr_err("Error %d reading opal-interrupts array\n", rc);
-		goto out_free;
+	/* Allocate an IRQ resources array */
+	opal_irqs = kcalloc(opal_irq_count, sizeof(struct resource), GFP_KERNEL);
+	if (WARN_ON(!opal_irqs)) {
+		rc = -ENOMEM;
+		goto out;
 	}
 
-	/* It's not an error for the names to be missing */
-	of_property_read_string_array(opal_node, "opal-interrupts-names",
-				      names, opal_irq_count);
+	/* Build the resources array */
+	if (old_style) {
+		/* Old style "opal-interrupts" property */
+		for (i = 0; i < opal_irq_count; i++) {
+			struct resource *r = &opal_irqs[i];
+			const char *name = NULL;
+			u32 hw_irq;
+			int virq;
+
+			rc = of_property_read_u32_index(opal_node, "opal-interrupts",
+							i, &hw_irq);
+			if (WARN_ON(rc < 0)) {
+				opal_irq_count = i;
+				break;
+			}
+			of_property_read_string_index(opal_node, "opal-interrupts-names",
+						      i, &name);
+			virq = irq_create_mapping(NULL, hw_irq);
+			if (!virq) {
+				pr_warn("Failed to map OPAL irq 0x%x\n", hw_irq);
+				continue;
+			}
+			r->start = r->end = virq;
+			r->flags = IORESOURCE_IRQ | IRQ_TYPE_LEVEL_LOW;
+			r->name = name;
+		}
+	} else {
+		/* new style standard "interrupts" property */
+		rc = of_irq_to_resource_table(opal_node, opal_irqs, opal_irq_count);
+		if (WARN_ON(rc < 0)) {
+			opal_irq_count = 0;
+			kfree(opal_irqs);
+			goto out;
+		}
+		if (WARN_ON(rc < opal_irq_count))
+			opal_irq_count = rc;
+	}
 
 	/* Install interrupt handlers */
 	for (i = 0; i < opal_irq_count; i++) {
-		unsigned int virq;
-		char *name;
-
-		/* Get hardware and virtual IRQ */
-		virq = irq_create_mapping(NULL, irqs[i]);
-		if (!virq) {
-			pr_warn("Failed to map irq 0x%x\n", irqs[i]);
-			continue;
-		}
+		struct resource *r = &opal_irqs[i];
+		const char *name;
 
-		if (names[i] && strlen(names[i]))
-			name = kasprintf(GFP_KERNEL, "opal-%s", names[i]);
+		/* Prefix name */
+		if (r->name && strlen(r->name))
+			name = kasprintf(GFP_KERNEL, "opal-%s", r->name);
 		else
 			name = kasprintf(GFP_KERNEL, "opal");
 
+		if (!name)
+			continue;
 		/* Install interrupt handler */
-		rc = request_irq(virq, opal_interrupt, IRQF_TRIGGER_LOW,
+		rc = request_irq(r->start, opal_interrupt, r->flags & IRQD_TRIGGER_MASK,
 				 name, NULL);
 		if (rc) {
-			irq_dispose_mapping(virq);
-			pr_warn("Error %d requesting irq %d (0x%x)\n",
-				 rc, virq, irqs[i]);
+			pr_warn("Error %d requesting OPAL irq %d\n", rc, (int)r->start);
+			kfree(name);
 			continue;
 		}
-
-		/* Cache IRQ */
-		opal_irqs[i] = virq;
 	}
-
-out_free:
-	kfree(irqs);
-	kfree(names);
-out:
+	rc = 0;
+ out:
 	of_node_put(opal_node);
 	return rc;
 }